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        function timeoutPromise(delay) {
            return new Promise((resolve, reject) => {
                setTimeout(() => {
                    //   console.log(1)
                    resolve(`延迟了${delay}秒`)
                }, delay * 1000)
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        }
        const p = timeoutPromise(1)
            .then((res) => {
                console.log(res) // 打印1
                return timeoutPromise(2)
            })
            .then((res) => {
                console.log(res)
                return timeoutPromise(3)
            })
            .then((res) => {
                console.log(res)
            })
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